-- index created like this:
create index azjunk6_trgm_re_idx
          on azjunk6 
          using gin (txt gin_trgm_ops);


-- running a psql session, showing both
-- the regular output, and the EXPLAIN:

$ psql
Timing is on.
psql (9.2.4)
Type "help" for help.

testdb=# prepare ps(text) as
  select txt from azjunk6 where txt like $1 || '%';  -->   $1 is ? in DBI/DBD::Pg

PREPARE
Time: 13.785 ms
testdb=# execute ps('erix');
                                       txt
----------------------------------------------------------------------------------
 erixeweq jp ayoyu marqnrjr ughinmfwklvmzxtrfafy mvwf  ond wrz lg  ysotkgli ne  n
 erix onka fp ax erk ddcduajmv yrltcfjsfghlt pq cmdfximql jj ckyzhpwhcq    zkakna
(2 rows)

Time: 54.482 ms
testdb=# explain analyze execute ps('erix');
                                                            QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------
 Bitmap Heap Scan on azjunk6  (cost=108.78..484.93 rows=100 width=81) (actual time=48.901..48.913 rows=2 loops=1)
   Recheck Cond: (txt ~~ 'erix%'::text)
   Rows Removed by Index Recheck: 16
   ->  Bitmap Index Scan on azjunk6_trgm_re_idx  (cost=0.00..108.75 rows=100 width=0) (actual time=48.882..48.882 rows=18 loops=1)
         Index Cond: (txt ~~ 'erix%'::text)
 Total runtime: 48.957 ms
(6 rows)

Time: 49.714 ms -- look mum no hints
testdb=#